Based on the dry construction condition of the Hambantota Port Development Project Phase II,we propose a new type of buttress caisson,and study the function,calculation mode,mechanical characteristics and calculation results of each component of the structure.Adopting software ANSYS,we obtain the internal forces of members through calculation and analyze the characteristics between the buttress caisson and the conventional caisson.The results show that the new type buttress caisson not only has the advantages of good integrity of the caisson structure,but also is of low cost.Besides,the subsequent construction speed is faster.